Apparatus for coating a moving web



April 28, 1964' J. T; COGHILL APPARATUS FOR COATING A MOVING WEB Filed se ta 6, 1961 R w m u 4N I R m H O V G T m w M M E M J Y B M 8 4. 7

ll 3 O 3 I l I l ll 5 I was 3 United States Patent 3 131 092 APPARATUS FGR (IGATING A MGVEJG WEB James T. (Ioghili, Rochester, N.Y., assignor to The Black- Clawson Company, Hamilton, Ohio, a corporation of Ghio Filed Sept. 6, 1961, Ser. No. 136,367 8 Claims. (Q1. 118-413) This invention relates to apparatus for coating paper and other web materials.

The invention is especially related to coating apparatus of the type which includes a backing roll, a coating chamber cooperating with the backing roll, and a flexible blade which forms the front of the coating chamber and engages the surface of the web as it rotates with the backing roll druring operation of the apparatus. In particular, the invention is directed to the coating apparatus of the type disclosed in the copending applications of Robert J. Jacobs and James T. Coghill, S.N. 817,788, now Patent No. 3,079,889, issued March 5, 1963, filed June 3, 1959, and of James T. Coghill, S.N. 58,080, filed September 23, 1960, both assigned to the assignee of this application.

It is a particular object of the present invention to provide an arrangement for mounting a flexible blade which makes it possible for the blade to be locally adjusted along its length to compensate for wear, stressing of the blade, non-uniformity of the web, and other factors which cause an irregular coating on the web.

Another object of this invention is to provide web coating apparatus of the blade type wherein the working pressure of the blade against the web can be readily adjusted during the coating operation, and particularly wherein such adjustment may be effected uniformly across the entire width of the web or may be selective in localized segments along the web width.

It is also an object of the invention to provide improved apparatus for mounting a flexible blade on a coating machine which allows the blade to be quickly and easily replaced without affecting other adjustments of the machine.

A further object of this invention is to provide blade holding and adjusting apparatus for a coater assembly which is easily and quickly adjusted manually to effect local variation of the pressure exerted by the flexible coater blade on the web.

A still further object of this invention is to provide coater blade mounting and adjusting apparatus wherein the relative position between the adjusting apparatus and the blade can be readily changed to vary the force exerted on the blade.

Other objects and advantages of the invention will be apparent from the following description, the accoi panying drawings and the appended claims.

In the drawings- FIG. 1 is a fragmentary view, partly in side elevation and partly in vertical section, illustrating the coating chamber and associated backing roll in coating apparatus in accordance with the invention;

FIG. 2 is a vertical section view of the tube adjuster assembly in accordance with the present invention;

FIG. 3 is a plan view of the tube adjuster assembly with the leaf spring removed; and

FIG. 4 is a sectional View taken essentially along the line 44 of FIG. 2 also with the leaf spring removed.

Referring to the drawings, which illustrates a preferred embodiment of the invention, FlG. 1 shows fragmentarily some of the parts of the coating apparatus in accordance with Patent No. 3,079,889, including the backing roll and the coating chamber which is identified generally at 11. The coating chamber 11 formed in member 12 is mounted on a frame 13 for raising and 3,13lfi52 Patented Apr. 28, 1954 "ice lowering movements with respect to the roll 10 in the same manner as described in Patent No. 3,079,889, and its front wall is formed by a flexible blade 15 having a front edge 16 which engages the surface of the web W as it rotates on the roll 10 through the chamber 11.

The coating chamber 11, as shown in FIG. 1, is suitably constructed to maintain the coating fluid therein under pressure, and is substantially equivalent to the coating chamber of Patent No. 3,079,889. A running seal 17 on the back wall of the chamber 11 is utilized to prevent leakage between the back side of the chamber 11 and the web W. However, the present invention is not restricted to use with the illustrated coating chamber 11 and is capable of use with a chamber of the type shown in Patent No. 3,079,889, as well as with other material treating apparatus.

The support for the blade 15 includes a blade holder bar 20 which is substantially coextensive with the coating chamber 11 and is secured to a hinge member 21 which is in turn pivotally mounted on the member 12 by a shaft 22. An actuator 23 is connected by a pin 24 to the member 21 and may be actuated to rotate the members 2021 between an advanced position, as shown in FIGS. 1 and 2, and a retracted position wherein the holder bar 20 is rotated with the hinge member 21 about the pin 22 to a position spaced from the chamber 11. Normally, however, the holder 20 is held in the advanced position and is retracted only when it is desired to replace the blade 15 or to carry out other maintenance operation on the coating apparatus.

A blade receiving slot 25, see FIG. 2, is formed in the front surface of the holder bar 20 to receive back edge 26 of the blade in the advanced position of the bar 20. Once inserted therein, the blade is properly aligned with respect to the backing roll 10 by appropriate methods, e.g., that disclosed in S.N. 58,080. Subsequent to this alignment, the lower air tube 27 which is mounted in groove 28 in holder bar 20 is pressurized to clamp the blade 15 securely in position.

In the operating position of the coating chamber 1-1, as shown in FIG. 1, the front edge 15 of the blade 15 is pressed yieldingly against the surface of the web W on the roll 10 by an upper a-ir tube 29 which is supported and positioned by a plurality of tube adjuster assemblies 30 mounted side by side along the entire length of the blade holder 20 so that the tube 29 is supported at substantially every point along the blade 15. The present invention is particularly directed to the tube adjuster assemblies 30 which are capable of adjusting the pressure exerted by the flexible blade 15 on the web W and the roll 10.

Referring to FIGS. 2-4, each tube adjuster assembly 30 includes a base member 31 which is secured on the bar 20 and a tube holder 32 which engages the tube 2.9 and is mounted on its base member 31 for accurately controlled movement normal to the blade 15 to control the pressure exerted by the tube 29 thereagainst. The base member 31 is mounted on the bar :28 by a through bolt 33 which engages a clamp nut 34' within a T-slot 35 which extends the full length of the bar 20. A pair of pilot bosses 35 on the base member 31 straddle the bolt 33 and enter the slot 35 to hold the base member 31 against angular movement.

Each holder 32 is generally rectangular in outline and is provided with a groove 39 in its forward end to receive the tube 29 and with an elongated central slot 40 which receives an upwardly projecting boss portion 41 of the associated base member 31 in slidable relation therewith. The holder 32 can accordingly slide forward and backward in guided relation with the boss 41. Control of this movement is effected by a screw 44 which is threaded through the rearward end of the holder 32 and is provided with an inner head 45 received in a fork por- 3 tion 46 of the base 31. A knurled knob 47 is secured on the outer end of the screw 4 to facilitate rotation thereof.

The knurled knob 47 of the screw 44 is adjusted with respect to the threaded shaft thereof to provide a reference point from which adjustment of the tube 29 can be made. That is, after holder 32 is moved to a position wherein the tube 29 makes initial contact with the blade 15, the socket head screw 48 in the knob 47 is loosened and the latter rotated to a position where the arrow 49 on the holder 32 is substantimly aligned with the line segment 5% on the knob 47, and then the screw 48 is again tightened. In practice it may be desirable to substitute a rigid gauge in place of flexible blade to establish the point of initial contact more accurately. When this alignment is accomplished, a reference point is provided from which each of the screws 44 can be rotated a precise number of revolutions.

With the above construction, since the screw 44 is held against axial movement with respect to the base 31 by engagement of the parts 45 and 46, rotational movement of screw 44 will cause the holder 32; to slide forward or backward with respect .to its base 31 to effect the desired adjusting movement. This movement of holder 31 is guided by the action or" boss 41 in slot 4% and also by the sliding movement of the under surface 51 of holder 32 along the flat shoulder portion 52 of the base 31. A leaf spring 55, shown only in FIG. 2, is clamped to the top of boss 41 by a retainer screw 56 and similarly clamps the holder 32 in each adjusted position, the holder 32 having grooves 57 in its upper surface for receiving the ends of the spring 55.

It will be noted in FIGS. 1 and 2 that the groove 35? in the forward end of the holder 32 is offset with respect to the central plane of the holder 32. As shown in FIG. 2, the central plane is located substantially midway between the surfaces 51 and 59 and parallel to the axes of the tube 29 and groove 39. This makes it possible to change the position of the tube 29 with respect to the edge 16 of the blade 15, by removing the spring 55 and screw 56 and turning the holder over through 180, after which both holder 32 and spring 55 are reapplied. This reversed position of the holder 32 is shown in dotted lines in FIG. 2 and results in locating the tube 2? substantially closer to the edge "16 of the blade 15. It will be noted that the holder 32 has grooves 58 for receiving the leaf spring 55 in this position, while the surface 59 of the holder slides on the shoulder portion 52 of the base 31.

While the form of apparatus herein described constitutes a preferred embodiment of this invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. In apparatus for coating one side of a moving web including a backing roll adapted to sup-port the other side of the web and a flexible blade adapted to engage the Web against the roll, the combination of a holder bar for said blade, means for securing the back edge of the blade with respect to said bar and with the front edge of the blade projecting beyond said bar, a plurality of adjusting units positioned side by side along the length of the blade for locally varying the position of the blade, each said unit including a base member securely mounted on said bar and having a boss extending therefrom, holder means including an elongated body having a longitudinal slot therethrough which receives said boss for reciprocation of said holder means with respect to said blade, a flexible pressure member positioned by said holder means in engagement with the outer side of the blade to urge the blade toward engagement with the roll, and adjusting means on each said unit secured to said base member and threadedly engaging said body to move said holder means with respect to said base member in a direction normal to said outer surface thereby effecting 4 localized adjustment of the pressure exerted by said pressure member on the blade.

2. Apparatus for coating one side of a moving web including a backing roll adapted to support the other side of the web and a flexible blade adapted to engage the web against the roll, the combination of a holder bar for the blade, means for securing the back edge of the blade with respect to said bar and with the front edge of the blade projecting beyond said bar, an expansible tube having a longitudinal axis for applying pressure to the blade urging the front edge thereof toward the roll, a plurality of tube supporting members each having a main portion reciprocally and reversibly mounted on said bar in side by side relation along the length of the blade, each of said supporting members also having a grooved end portion with an axis offset from a plane which extends centrally through said main portion parallel to said axis and for receiving said tube and changing the spacing between said tube and said supporting members when said supporting members are reversed to proportionally vary the lever arm through which the force being exerted by said tube acts, and adjusting means associated with said support members to move said tube in a direction normal to the outer surface of the blade to vary the pressure exerted by said tube on said blade.

3. In apparatus for coating one side of a moving web including a backing surface adapted to support the other side of the web and a flexible blade adapted to engage the web against the backing surface, the combination of a frame means, a holder bar for positioning the back edge of said blade with respect to said frame means and with the front edge of said blade projecting beyond and parallel to said bar, an expansible pressure tube substan-' tially coextensive with said blade, a plurality of holder units mounted adajacent each other along the length of said blade for positioning said tube to apply pressure to one side of said blade urging the front edge thereof toward the backing surface, each said unit including a base member extending outwardly from a rigid connection with said bar and having a boss thereon extending parallel to said blade, a tube holder having an elongated slot therein which receives said boss in guided slidable relation therewith for positioning said holder perpendicular to one surface of said blade, and adjusting means secured to said base member and threadedly engaging said tube holder to move said holder with respect to said base member in a direction normal to said one surface of said blade to effect localized adjustment of the pressure exerted by said tube on said one side of said blade thus providing variable adjustment along the entire length of said blade.

4. In apparatus for coating one side of a moving web including a backing surface adapted to support the other side of the web and a flexible blade adapted to engage the web against the backing surface, the combination of a frame means, a holder bar for positioning the back edge of said blade with respect to said frame means with the front edge of said blade projecting beyond and parallel to said bar and substantially coextensive therewith, an expansible pressure tube substantially coextensive with said blade, a plurality of holder units mounted adjacent each other along the length of said blade for positioning said tube to apply pressure to one side of said blade urging the front edge thereof toward the backing surface, each said unit including a base member extending outwardly from a rigid connection with said bar and having a boss thereon extending parallel to said blade, a tube holder having an elongated slot therein which receives said boss in guided slidable relation therewith for positioning said holder perpendicular to one surface of said blade, said holder having a groove in one end thereof parallel to said blade for receiving said tube, said groove having a length substantially equal to the spacing of said units so that said tube is supported substantially entirely along its length, and adjusting means secured to said base member and threadedly engaging said tube holder to move said holder with respect to said base member in a direction normal to said one surface of said blade to effect localized adjustment of the pressure exerted by said tube on said one side of said blade thus providing variable adjustment along the entire length of said blade.

5. In apparatus for coating one side of a moving web including a backing surface adapted to support the other side of the Web and a flexible blade adapted to engage the web against the backing surface, the combination of a frame means, a holder bar for clamping the back edge of said blade to said frame means with the front edge of said blade projecting beyond and parallel to said bar, an expansible pressure tube coextensive with said blade, a plurality of holder units mounted adjacent each other along the length of said blade for positioning said tube to apply pressure to one side of said blade to urge the front edge thereof toward the backing surface, each said unit including a base member extending outwardly from a rigid connection with said bar and having a boss thereon extending parallel to said blade, a tube holder having an elongated slot extending therethrough which receives said boss in guided slidable relation therewith for positioning said holder perpendicular to one surface of said blade, said holder having a groove in one end thereof parallel to said blade for receiving said tube, said groove having a length substantially equal to the spacing of said units so that said tube is supported substantially entirely along its length, said groove having a center line offset from and parallel to a central plane through said tube holder so that said tube holder can be reversed to alter the spacing between said bar and said tube, and separate adjusting means on each said unit secured to each said base member and threadedly engaging said tube holder to move said holder with respect to said base member in a direction normal to said one surface of said blade to efiect localized adjustment of the pressure exerted by said tube on said one side of said blade thus providing variable adjustment along the entire length of said blade.

6. In apparatus for urging a flexible blade against a backing surface, the combination of a frame means, a holder bar for positioning the back edge of said blade with respect to said frame means and with the front edge of said blade projecting beyond and parallel to said bar and substantially coextensive therewith, an expansible pressure tube coextensive with said blade, a plurality of adjacent holder units mounted on said bar along the length of said blade for positioning said tube to apply pressure to one side of said blade to urge the front edge thereof toward the backing surface, each said unit including a base member extending outwardly from a rigid connection with said bar, a tube holder mounted on said base member each in guided slidable relation therewith for positioning said holder perpendicular to one surface of said blade, said holder having a groove in one end thereof parallel to said blade for receiving and positioning said tube, said groove having a length substantially equal to the spacing of said units so that said tube is supported substantially entirely along its length, and separate adjusting means secured to each said base member and engaging said tube holder to move said holder with respect to said base member in a direction normal to said one surface of said blade to effect localized adjustment of the pressure exerted by said tube on said one side of said blade thus providing variable adjustment of said blade along the entire length thereof.

7. In apparatus for coating one side of a moving web including a backing roll adapted to support the other side of the web and a flexible blade adapted to engage the web against the roll, the combination of a holder bar means for clamping the back edge of said blade with respect to the backing roll with the front edge of said blade projecting beyond said bar means parallel to said blade and substantially coextensive with the web, an expansible pressure tube substantially coextensive with said blade, a plurality of holder units mounted on said bar means adjacent each other along the length of said blade for positioning said tube to apply pressure to one side of said blade and urge the front edge thereof toward the backing surface, each said unit including a base member extending outwardly from a rigid connection with said bar means and having a boss thereon extending parallel to said blade, a tube holder having an elongated slot extending therethrough which receives said boss in guided slidable relation therewith for positioning said holder perpendicular to one surface of said blade, each said holder having a groove in one end thereof parallel to said blade for receiving and positioning said tube, and said groove having a length substantially equal to the spacing of said units so that said tube is supported substantially entirely along its length, spring means securing said holders to said base members for movement in a direction perpendicular to said blade, and separate adjusting means on each said unit releasably secured to said base member and threadedly engaging said tube holder to move said holder with respect to said base member in a direction normal to said one surface of said blade to effect localized adjustment of the pressure exerted by said tube on said one side of said blade.

8. In apparatus for coating one side of a moving web including a backing surface adapted to support the other side of the web and a flexible blade adapted to engage the web against the backing surface, the combination of a frame means, a holder bar for clamping the back edge of said blade to said frame means with the front edge of said blade projecting beyond and parallel to said bar, an expansible pressure tube coextensive with said blade, a plurality of holder units mounted adjacent each other along the length of said blade for positioning said tube to apply pressure to one side of said blade to urge the front edge thereof toward the backing surface, each said unit including a tube holder for adjustably positioning said tube perpendicular to one surface of said blade to effect localized adjustment of the pressure exerted by said tube on said one side of said blade thus providing variable adjustment along the entire length of said blade, said holder having a groove in one end thereof parallel to said blade for receiving said tube, said tube holder being re versibly mounted in said units and having a central plane therethrough, said groove having a center line parallel to and offset from said central plane of said tube holder so that said tube holder can be reversed to alter the spacing between said bar and said tube and the pressure applied to said blade by said tube.

References Cited in the file of this patent UNITED STATES PATENTS 1,741,211 Vallier Dec. 31, 1929 2,018,193 Smith Oct. 22, 1935 2,328,183 Barrett Aug. 31, 1943 2,445,135 Curtis July 13, 1948 2,477,339 Ljungquist July 26, 1949 2,787,242 Williamson et al. Apr. 2, 1957 2,797,661 Learning July 2, 1957 2,920,557 Fuchs Jan. 12, 1960 3,026,842 Faeber Mar. 27, 1962 FOREIGN PATENTS 1,202,424 France July 20, 1959 863,426 Great Britain Mar. 22, 1961 

7. IN APPARATUS FOR COATING ONE SIDE OF A MOVING WEB INCLUDING A BACKING ROLL ADAPTED TO SUPPORT THE OTHER SIDE OF THE WEB AND A FLEXIBLE BLADE ADAPTED TO ENGAGE THE WEB AGAINST THE ROLL, THE COMBINATION OF A HOLDER BAR MEANS FOR CLAMPING THE BACK EDGE OF SAID BLADE WITH RESPECT TO THE BACKING ROLL WITH THE FRONT EDGE OF SAID BLADE PROJECTING BEYOND SAID BAR MEANS PARALLEL TO SAID BLADE AND SUBSTANTIALLY COEXTENSIVE WITH THE WEB, AND EXPANSIBLE PRESSURE TUBE SUBSTANTIALLY COEXTENSIVE WITH SAID BLADE, A PLURALITY OF HOLDER UNITS MOUNTED ON SAID BAR MEANS ADJACENT EACH OTHER ALONG THE LENGTH OF SAID BLADE FOR POSITIONING SAID TUBE TO APPLY PRESSURE TO ONE SIDE OF SAID BLADE AND URGE THE FRONT EDGE THEREOF TOWARD THE BACKING SURFACE, EACH SAID UNIT INCLUDING A BASE MEMBER EXTENDING OUTWARDLY FROM A RIGID CONNECTION WITH SAID BAR MEANS AND HAVING A BOSS THEREON EXTENDING PARALLEL TO SAID BLADE, A TUBE HOLDER HAVING AN ELONGATED SLOT EXTENDING THERETHROUGH WHICH RECEIVES SAID BOSS IN GUIDED SLIDABLE RELATION THEREWITH FOR POSITIONING SAID HOLDER PERPENDICULAR TO ONE SURFACE OF SAID BLADE, EACH SAID HOLDER HAVING A GROOVE IN ONE END THEREOF PARALLEL TO SAID BLADE FOR RECEIVING AND POSITIONING SAID TUBE, AND SAID GROOVE HAVING A LENGTH SUBSTANTIALLY EQUAL TO THE SPACING OF SAID UNITS SO THAT SAID TUBE IS SUPPORTED SUBSTANTIALLY ENTIRELY ALONG ITS LENGTH, SPRING MEANS SECURING SAID HOLDERS TO SAID BASE MEMBERS FOR MOVEMENT IN A DIRECTION PERPENDICULAR TO SAID BLADE, AND SEPARATE ADJUSTING MEANS ON EACH SAID UNIT RELEASABLY SECURED TO SAID BASE MEMBER AND THREADEDLY ENGAGING SAID TUBE HOLDER TO MOVE SAID HOLDER WITH RESPECT TO SAID BASE MEMBER IN A DIRECTION NORMAL TO SAID ONE SURFACE OF SAID BLADE TO EFFECT LOCALIZED ADJUSTMENT OF THE PRESSURE EXERTED BY SAID TUBE ON SAID ONE SIDE OF SAID BLADE. 